The invention relates to a local area network comprising at least one bridge terminal, which bridge terminal is provided for transmitting data between the terminals of at least two sub-networks via a wireless medium.
Such a local area network comprising a plurality of sub-networks is known from DE 196 37 026 A1. A sub-network contains a plurality of terminals which exchange via a radio transmission medium (wireless medium) cells generated in the asynchronous transfer mode. Data are transmitted between two sub-networks via a bridge terminal. How the data are processed in such a bridge terminal is not further described in said document.
It is an object of the invention to provide a cost-effective bridge terminal for connecting at least two sub-networks in a local area network.
The object of the invention is achieved by a local area network of the type defined in the opening paragraph in that the bridge terminal is alternately connected to the sub-networks for exchanging data, and in that the bridge terminal contains an intermediate data store provided for temporarily storing received data for an unconnected sub-network.
According to the invention, the bridge terminal is connected to only one sub-network during a time slot for data exchange. Data for another sub-network are stored in an intermediate store and will not be read out until the bridge terminal is connected to the other sub-network in a next time slot. Arranging a bridge terminal in such a way that always only one sub-network is connected to the bridge terminal means that further components may be omitted. The data, which are transmitted inside the local area network, may be generated in accordance with a packet transfer method. The packets may be transmitted as a whole or as sub-packets via the wireless medium after further data have been added. A wireless medium is understood to mean a radio, infrared, ultrashell transmission, etc. As a packet transfer method may be used, for example, the asynchronous transfer mode (ATM), which generates fixed-length packets, which are called cells.
The system explains the reading process from the intermediate store. The data are read from the intermediate store in the order in which they have been written.
The system describes the process of the termination and beginning of a connection of the bridge terminal to two different sub-networks.
The bridge terminal cannot only exchange data with two sub-networks. The requirements for a data exchange with M sub-networks (Mxcex5N, Mxe2x89xa62).
The structure of the bridge terminal works with different carrier frequencies is shown in FIG. 7.
The invention further also relates to a bridge terminal for transmitting data between the terminals of at least two sub-networks of a local area network via a wireless medium. The bridge terminal is alternately connected to the sub-networks for exchanging data and contains an intermediate store, which is provided for temporarily storing received data for an unconnected sub-network.
These and other aspects of the invention are apparent from and will be elucidated with reference to the embodiments described hereinafter.